Sharpening device for safety razor blades



Jan. 22, 1935. c. E. BEARDSLEY 1,988,474

SHARPENING DEVICE FOR SAFETY RAZOR BLADES Filed March 24, 1954 INVENTOR M 52- Ma 5 m, BY

ATTORNEYS Patented Jan. 22, 1935 lei -W SHARPENING' DEVICE FOR SAFETY RAZOR BLADES 7 v Charles E. Beardsley, Bethlehem, Conn., as'signor to Scovill Manufacturing Company, Waterbury, Conn., a corporation of Connecticut l Application March 24, 1934, SerialNo. 717,162

14 Claims.

n sharpened may be interposed. The holder shouldbe provided with suitable means to serve as a rest for the blade and with means whereby the blade may be held'in a definite position on the holder. The sharpening tool should have abrasive portions adapted to lie along the marginal portions of the blade, and such portions should be inclined with respect to the surfaceof the blade at acute angles appropriate for sharpening purposes.

mutually interengaging portions adapted to limit the movement of the holder along the surface of an interposed blade in every direction while permitting a sufficient amount of such movement in any desired direction to effect a satisfactory conditioning of the edges of the blade.

The relations of the parts of the sharpening device should be such that the tool may be readily moved in a direction such as to have a material crosswise component of movement over the edges of the blade, but, if desired, the movement-limiting means may be such as to permit a sharpening movement of the tool over the surface of the blade in any direction including a direction 35 lengthwise of the blade.

The tool and holder may, if desired, be connected'together insuch manner that they may notice detached one from the other, but the connection should be such that they may be readily 40 separated to an extent such as to facilitate the positioning of a blade in the holder and the 'removal of the blade from the holder after it has been-sharpened. The connection should also be such as to permit the tool to'at all times assume a position such that it will make contact with the edges of an inserted blade from end to end. his may most readilybe accomplished by making either the tool. or the'holder of a weight such; that, when the sharpener is positioned with that 50 part uppermost, force of gravity alone may-be relied upon to produce a satisfactory degree'of' sharpening pressure between the "tool and the.

blade. The upper part of the sharpening device which'thus merely rests upon the blade, which is 55 in turn supported by the other'part of the sharp- The tool and holder should be provided withening device, may'freely move in any direction along the surface of the blade; and such move-- ment may include a slight rocking movement determined by the zones of contact between the inclined surfaces of thetool and'the marginal portions of the vblade. It is of no m'aterial importance which element of thesharpener is designed to be uppermost. 'What is of importance is that the lowermost element be ofa form such that it maybe vibrated when held by the user in order to reciprocate the upper element and thus produce the sharpening movementbetween the two elements without interferingwith the desired amplitude ofrelative movement between the parts. 1 The device maybe used in sharpeningblades, having either one edge or two edges. The sharpening tool may be constructed entirely of abrasive material. If used to sharpen a' two-edged blade, atleast the two in'clined'surfaces which move over the edges of the blade must be of abrasive,

material. If used -to sharpen f a single-edged blade, it is s'uflicient thatthe portion of the tool which" contacts with the edge to be'sharpened be' of abrasive material. g r

It is an object of the invention 'to provide a sharpener of the above-described character of which the part of the holder which serves as'a blade rest is slightly crowned from end to end instead of being perfectly level so that the end portions'of the edges of the blade may yield slightly when subjected to' the sharpening pressure of the sharpening tool.

It is afurther objectof the invention to provide a blade sharpener of the above-described character of which the portion of the sharpening tool which faces the central portion of the bladev will be .so positioned with respect to the surface of the blade during a sharpening operation as to opposeany undue bowing of :the blade at its "center which might: be caused by the opposed forces exerted against the blade along its marginal portions by the blade-contacting por tions' of the holder and the portions of the'tool, which engage the "edges ofthe blade.

Thefeature of crowningfthe part of the holder which serves asv ablade rest and'the-feature of providing the tool with means for preventing the undue bowing of the bladeat the, center are of importance as. improvements whether used inde-.

pendently of each other or in combination; It

' has beenfound, however, that the best results yield slightly while at the same time preventing undue bowing of the blade at the center.

It is a still further object of the invention to provide the tool and holder with interengaging parts which will permit a limited degree of sharpening movement in every direction and which will also serve as a hinged attaching means adapted to'allow one .parttobe swung with respect to'tlie' other part about one of its margins to an extent of approximately ninety degrees to facilitate the insertionand removal of a blade and to prevent further swinging movementof one part with respect to the other so as to hold one Fig. 3 is a perspective view of the sharpening device illustrated by Fig s. 1 and ;2, the parts being represented as having been closed to the relative positions appropriate for sharpenin purposes;

Fig.4 is a large-scale, longitudinal, cross-sectional view of the sharpener illustrated by Figs, 1, 2 and 3.

Fig. 5 is a large-scale viewfof a portion of one end of the sharpener illustrated by Figs. 1 to 4,

, inclusive.

' lihepreferred form of the invention illustrated by. means of the abovedescribed drawing may comprise a blade-rholder20 and asharpening tool 21;,between which-may be inserted a blade 22 to be sharpened, vtheiblade being represented in brokenlines in Figs,- land 2 and in full lines in thecross-sectional view, Fig; 4..

As ameans of spacingthe edges of the blade msdJaWn p n hehol e o ha p tions of the sharpening tool may-move freely over its edges, a part of the holder which may com- Any appropriate blade-positioning means may.

prise a single element or a number of elements maybe raised above the general surface of the holder so as t0 provide a backing against which As illustrated,

onesurface of the blade may rest. by Figs. 1, 2 and l an appropriate form of backing mavcom'priseapair of upstandingribs 23 so positioned that their outer margins-willbe spaced inwardlyfro nthe adjacentedges of, a blade seated on the rest. 7 i

be provided to hold a bladeain a predetermined position over the backing, means 23. Such bladepositioning means may comprise-'apair of up standing lugs 24 solocatedas to pass through spaced openings commonly? provided in safety razor blades of forms wellknownin the prior art. The character of the blade positionifig meansis not of importance, What isfof .c'onsequencejis that somemeans shall be provided to engage spaced parts of the bladefwhenin'the desiredpoa sitiononthe blade-bacEingineans-and prevent it from sliding over the "backing means during a sharpening operationi I I The blade-sharpening element may comprise a slab of suitable abrasive material having-sportions 25' slightly inclined: onerelatively to the other so as to bedisposed at. aoutesharpening'; anglesiwithrespect to the. surface of the blade. when in contact with its edges, and an intervenas blade sharpening tool 21 may freely move. Movement of the sharpening tool in a direction perpendicular to the lengthwise direction of the flanges is dependent upon the difference between the length of the sharpening tool and the clear distance between the inner surfaces of the flanges. As a means of limiting movement of the sharpening tool in a direction parallel with the flanges, one of the elements of the sharpener, the tool, may be provided with apair of outwardly-extending lugs 28 which may pass through a pair of slots 29 located in corresponding end portions of the flanges 2'7. These lug-and-slot connections may be relied upo-nto limit the extent of movement of the sharpening tool in a direction parallel with the flanges without in any mannerinterfering with its. movement in a direction perpendicular to theflanges to the. extent permitted by the flanges. The lengths of the lugs 28 may be such thatthey will not be withdrawn from either of the slots 29 during the movement of the sharpening tool in its direction perpendicular to the flanges, and mayserve not only as a means of permanent connection between ,thetooland the holder and a means of limiting relative movement of said parts in a direction parallel with the flanges, but also as a hinge connection between said parts such as to permit one to be swung to a position substantially at right angles with respect to the other to facilitate the insertion or removal of a blade, as indicated in Figs. 1 and 2. 1

If desired, the blade-positioning elements 24. and the blade-backing ribs 23 may be symmetrically disposed with respect to an axis O-O, Fig.

1, slightly inclined as compared with the longitudinal edges of the holder, so that the tool may be given a sharpening movement which will have a predetermined lengthwise component and a predetermined longitudinal component with respect to the edges of the blade when vibratedin a direction parallel with the flanges of theholder.

However, by making the tool of a length material 1y less than the distance between the inner surfaces of the flanges, as best indicated in-Figs. 3 and 4;, the tool may be vibrated in a direction parallel with .the edges of the blade or at any desired angle with respect thereto. I

. It has been discovered that if the blade is seated against a backing means, all parts of which lie in the same plane when being sharpened by a tool having contact with its edges throughout their entire lengths, the edges are oversharpened along their end. portions and undersharpened along their central portions. It is one of the important objects of this invention to correct thislack of uniformity as to the effectiveness of the sharpening device, and this has been accomplished by slightly crowning-the blade-seating means, herein.disclcsed.as. the ribs 23, from end to end, as indicated to an exaggerated degree at 30. 30, Fig.

4. This crowning or rounding-01f .of the ribs 23 towards theirends permits the end portions of the edges of the-blade to. yield to a minute extent when subjected to pressure by the sharpening tool, thus reducing the sharpening friction at the end portions of the blade edges, and correspond-' ingly increasing the sharpening friction along the.

central portions of the blade edges, as a result of which the desired uniformity of sharpening from end to end of the edges of the blade is effected.

It has also been found that if the blade to be sharpened is relatively thin, the opposed forces set up by the pressure of the sharpeningtool along the edges of the blade and the pressure of the blade-seating means along zones spaced inwardly from the edges. may cause theblade to be bowed to an extent such as to reduce the sharpening angle betweenthe surface of the blade and the contacting portions of the tool to an extent such as to be detrimental. It'is an object of this invention to correct such a possible imperfection in the sharpener by so positioning a part ofthe tool adjacent the central portion of the blade that it will be engaged by the blade and oppose an undue extent of bowing of the same during .the sharpening operation. In the form .of the invention herein disclosed, the sharpening tool 21 is provided with an inset exterior strengthening plate 31 held in place by a fastening element comprising a shank 32 having ahead 33 at one end, separated from the plate 31 by a washer 34, and a disk 35 at its other end, thesurface of which is so positioned as to serve as themeans toprevent the undue bowing of the blade. .The head 33 and disk 35 may be secured to the ends of the shank 32 in any appropriate manner. The shank and one of said parts may be formed as a single integral structure, and the other part, herein shown as the disk, 35, may be secured thereto by a threaded connection which, if desired, may also be riveted to prevent accidental separation.

The head 33 may be knurled as indicated at 36, or may be otherwise adapted for use as a thumb or finger hold by means of which the sharpening tool may be moved with respect to the holder. The head, shank and disk therefore serve a double function in that these intimately associated elements of the sharpener provide means for manipulating the sharpening tool and means for opposing undue bowing of a blade during a sharpening operation.

It is not essential that the disk 35 be so positioned as to prevent any bowing whatever of the blade by the tool. It should preferably permit the blade to be very slightly bowed in order that thedisk may move along its curved surface during the rocking movement of the tool determined by the zones of contact between the edges of the blade and the overlying inclined portions of the tool. a

As a means of preventing the opening of the sharpen er without first moving the tool to a position such that the marginal portion whichbears the lugs 28 may clear the blade, the lugs may be given a rectangular form in cross-section, as shown, and the major axis of each may be of a length greater than the width of the groove.

size such as to accommodate the end of the lug.

The enlargement'38 at the side of the slot nearest the free edge of the flange should be of a sizev and form suchas to permit the end of the lug directedaway from the end of the flange to move freely as the lug is swung about the end which enters the enlargement 37 during the opening movement of the sharpener. Each of the abovedescribed slots 29 may be aptly referred to as of the form of a boot. The part of the slot 39 representing the sole of the boot is disposed towards the end of the flange; the enlargement 3'7 corresponds with the part representing the toe of the boot; the part 38 corresponds with the partrepresentative of the heel; and the narrow part of the slot 40 is the part which is representedby the. leg of the boot.1 V

In view of the rocking component of the movement of the tool over the blade in a crosswise direction due tothe inclination of thesharpening surfaces of the tool, the slots should be inclined,

as indicated in Fig. 5, in a manner which corresponds with the tilting of the leg of the boot representative of the slot upwardly towards thefree edge of the flange, the entire boot being rotated slightly in a clockwise direction, as illustrated in Fig. 5, about the toe 37.

In order that the parts may be arrested after venting rotation of the lug in a clockwise direction beyond the position indicated in Fig. 5. With the parts thus constructed, the sharpener may be held with either of its parts horizontal, as indicatedin Figs. 1 and 2, and the other part will remain in its opened position during the insertion or removal of ablade. Due, however, to the size and form of the enlargment 38 of the groove, the parts may be readily closed so as to assume the relative positions indicated in Fig. 3.

onds between the thumb and fingers, as indicated by broken lines in Fig. 3, after which the sharpener may be inverted and then opened so that the parts will assume the relative positions indicated in Fig. 2, with the blade lying upon the sharpening tool as indicated in broken lines. When so positioned the blade may be readilylifted by grasping it at its ends between the thumband finger, the holder turned to the position indi cated in Fig. 1, and the blade dropped onto the backing means of the holder in engagement with the positioning elements 24. then be'again closed and vibrated a few seconds after thus reversing the position of the blade in the sharpener. The sharpener may then again be inverted and opened to the position indicated in Fig. 2, from which the blade may be readily removed and inserted in the razor frame in readiness for use-in shaving. i

The sharpener may When a conditioningiof the'blade correspond-:

2 moved back and forth in any desired direction while exerting a slight pressure by application of the thumb or finger to the knurled'head 33.

After thus honing the blade it may be given a final treatment corresponding'with a 'stropping by again vibrating the sharpener a few seconds without applying additional pressure 7 to the sharpening tool. a

It is of no consequence which element of-th blade sharpener is designed to be uppermost during the sharpening operation, subjectto the condition that theelement intended to be uppermost, the sharpening tool in the form herein disclosed,

should be of sufficient weight to afford a satisfac tory sharpening pressure for a conditioning cor-' responding with a stropping of the blade, and the further condition that the lowermost element, the holder in the form herein disclosed,be of a form such that it may be held during the vibration of the sharpener without interfering with the relative movement of the upper part. 1 v

The invention is not intended to be limitedto the preferred form of the invention herein disclosed for purposes of illustration, but should be regarded ascovering modifications and varia tions thereof within the scope of the appended claims.

What is claimed is:-

l 1. A safety razor blade sharpener comprising, in" combination, a holder and a sharpening tool betweenwhich mayrbe interposed a blade to be sharpened, the-holder and tool having mutually interengaging portions 50' disposed as to limit the relative movements of the tool with respect to the holder along the surface of the blade in all directions, a limited relative movement of the tool and holder away from each other to an extent such as to :separate one of said parts from the surface of an interposed blade being unrestricted otherwise than by force of gravity, and theweight of one of said parts being suhicient, whenthe sharpener is disposed with that part uppermost, to serve as a means of maintaining a satisfactory degree-of sharpening pressure along-the zones of 7 contact between the tool andthe'margins of the.

blade, blade-positioning means comprisingfixed parts of the holder to engagespaced parts of the blade and hold it in a predetermined position, and

a trifling extent at their ends as the tool 'is'moved over them, the outer margins ,of the backing meansbeing spaced inwardly of the margins of, the blade so as to hold them away from the,

adjacent parts of the holder, the portions of the tool facing and lying along the marginal portions of a positioned blade being inclined at acute sharpening angles with respect to the surface of the blade, the portion of thetool facing the central portion of thepositioned blade being so dis,

posed as to make contact with the adjacentisurface of the blade and preventit from being materiallyibowed upwardly at the center when pressed along its margins by'theoverlying portiOIlS'jOf the tool, and the parts of'the tool and holder being prevented from moving towards each other only by the interposed blade, whereby the tool may be reciprocated along the surface of the blade, the movement of the tool relative to the holder being a composite one having a material crosswise component and a rocking component determined as to direction and extent by the zones of contact between the margins of the blade and the adjacent surface portions of the tool and by the interengaging portions. of the tool and holder. 7

,2. A safety razor blade sharpener comprising, in--combination, a holder and a sharpening tool between which may be interposed a blade to be sharpened; the holder andtool having mutually interengaging portions so. disposed as to limit the relative movements .of the tool with respect to the holder along the surface of the blade in all directions; blade-positioning means comprising fixed parts .of the holder to engage spaced parts of the blade andhold it in a predetermined position, and blade-backing means comprising a raised portion of the holder against which one surface of the positioned blade may rest, the outer margins of the backing means being spaced inwardly of themargins of the blade so asto hold themaway from the adjacent parts of the holder,

the portions of the tool facing and lying along the marginal portions of a positioned blade being inclined at acute sharpening angles with respect to the surface of the blade, the portion of the tool facing the central portion of the positioned blade beingJso disposed as to make contact with the adjacentsurface of the blade and prevent it from being materially bowed upwardly at the center when pressed along its margins by the overlying portions of, the tool, and the parts of the tool and holder being prevented from moving towards each other only by the interposed blade, whereby the tool may be reciprocated along the surface of the blade'to an extent dependent uponthe limiting effect of the interengaging portions of thegtool and holder, while the tool and holder are acted upon by opposed forces tending to move one towards the other.

3. A sharpener, as defined by claim 2, of which the interengaging portions of the tool and holder are so disposed as to'permit the tool to move along the surface of theblade in a. direction having a material crosswise component and a rocking component determined as to direction by the zones of contact between the marginsof the blade i and the adjacent surface portions of the tool.

4. A sharpener, as defined by claim 2, of which arelative movement of the tool and holder away from each othentoan extent such as to separate one of the saidiparts fromthe surface of an interposedbladej, is not restricted otherwise than by force of gravity, and of which the weight of one of the said'parts is sufiicient, whenthe sharp-' inner enlargement being of a size'and location all directions, said portions comprising a pair such as to serve as the part of the tool which prevents'any material upwardbowing of 'a blade during a sharpening operation.

6. A sharpener, as defined by claim 2, of which the backing means with which the marginal portions of an interposed blade makecontact between which may be interposed a blade to be sharpened, the holder and tool having mutually interengaging portions so disposed as'to limit the relative movements of the tool with respect ;to the holder along the surface of the blade in all directions, blade-positioning means *comprising fixed parts of the holder to engage spaoed parts of the blade and hold it in a predetermined position, and blade-backingv means'acomprising a raised portion of the holder against which, one surface of the positioned blade may rest, the outer margins of the backing means being spaced inwardly of the margins of the-blade so "as to hold them away from the adjacent parts of the holder, the portions of the tool facing and lying along themarginal portions of a positionedbla'de beinginclined at acute sharpening angles with respect to the surface of theblade, the backing means with which the marginal portionsof the blade make contact when pressed by the tool during a sharpening operation being very slightly crowned from end to end so as to permit the edges of the. blade to yield to a trifling extent at their ends as the tool is moved over them, and the parts of the tool and holder being prevented from moving towards each other only by the interposed blade, whereby the tool may be reciprocated along the surface of the blade to an extent dependent upon the limiting effect of the inter-engaging portions of the tool and holder, while the tool and holder are acted upon by opposed forces tending to move one towards the other.

8. A sharpener, as defined by claim 7, of which the interengaging portions of the tool and holder are so disposed as to permit the toolto move along the surface, of the blade in a direction having a material crosswise component and a rocking component determined as to direction by the zones of contact between the margins of the blade and the adjacent surface portions of the tool.

9. A sharpener, as defined by claim '7, of which a relative movement of the tool and holder away from each other, to an extent such as to separate one of the said parts from the surface of an interposed blade, is not restricted otherwise than by force of gravity, and of which the weight of one of the said parts is sufiicient, when the sharpener is positioned with that part uppermost, to serve as a means of maintaining a satisfactory degree of sharpening pressure along the zones of contact between the tool and the margins of the blade.

10. A safety razor sharpener comprising, in combination, a holder and a sharpening tool between which may be interposed a blade to be sharpened, the holder and tool having mutually interengaging portions so disposed as to limit the relative movements of the tool with respect to the holder along the surface of the blade in of flanges on one of said parts spaced at a sufand-slot connections between corresponding end portions of. the flanges of one of said parts and adjacent :portions of the other part adapted to serve as the means for limiting relative movements of said parts in directions parallel with said flanges and to serve as a hinge connection whereby one of said parts may be swun about one of its marginal portions relative to the other through an angleof approximately ninety degrees to facilitate theplacing of a blade between the holder and the tool and the removal .of a blade from ,sucha position, the relative sizes'and forms of the respective lugs and their slots beingsuch .as to permit free movement through such an angle but, such as to oppose angular movement .of greater extent.

11.,A sharpener, as defined by claim 10, of which the lugs are of non-circular form in crosssection having major axes which are longer than the widths of the slots, and of which the slots are enlarged at their opposite sides at the ends in whichnthe lugs are tobe positioned when the :.ficien't distance from each other-to permit-the other part to move freelylbetween them, and lugparts areto be swung to their open position, the

enlargements into which the parts of the lugs at the ends of the slots are to be turned being of a size suflicient to permit the lugs to enter and 'theopposite enlargements beingof a size and major axesof the lugs, so that the rotation of the lugs will be prevented after they have been turned to positions crosswise with respect to the slots.

12. A sharpener, as defined by claim 10, of which the lugs are of an oblong form in cross- -section, and of which each slot is of the form of aboo't having its sole directed towards the near end of the flange, its leg towards the far end of the flange, its toe towards the base of the flange, its heel towards the free edge of the flange, and the entire boot tilted up slightly at the leg end about the toe, the major diameter of each lug being of greater length than the width of the part of the slot represented by the leg of the boot, and also of greater length than the distance from the part of the slot corresponding with the frontof the leg near the toe to the back of the heel, the part corresponding with the toe of the boot being of a size such as to permit the lug to enter when turned crosswise of the slot, and the form and size of the part corresponding with the heel being such as to permit the lug to turn freely when in the end of the slot to a position substantially crosswise thereof, in which position further movement will be prevented by the interlocking engagement between the part of the lug which enters the partof the slot represented by the toe of the boot and the adjacent Walls of the slot.

13. A safety razor blade sharpener comprising, in combination, a holder and a sharpening tool between which may be interposed a blade to be sharpened, the holder and tool having mutually interengaging portions so disposed as to limit the relative movements 'of the tool with respect to the holder along the surface of the blade in all directions, said portions comprising a pair I of flanges on one ofsaid parts spaced at a sulficient-distancefrom each other toxpermit the other part to move 'freelyabetween them, and lug-and slot connections between corresponding end portions of the flanges of one of said parts and adjacent sportions of: theother part, adapted tosrveas the means 'forlimiting relative movements of said parts in directions parallel With the said flanges and to serve as a hinge connection whereby :one of said parts may be swung'about one ofits marginal portionsrelative to the other to facilitate the placing of a blade between the holdercandthe tool and the. removal of'a blade from isuch position,-the:fianges; on one of the sharpener parts beingspaced at a sufficient dise tance from the adjacent marginal portions of the other-part to-permit :a limited degree of sharpening movement in a direction perpendicular to the flanges, and the lugs being of a length such that theywill not be withdrawn from the slots in the flanges during such movement.

14. Asafety razorbladesharpener comprising, in, combination; a-holder and a sharpening tool between which may be interposed a blade'to. be sharpened, the holder and .toolhaving mutually interengagingzportions so disposed as to limit the relative movements of thetool with respect to the holder along thesurfacelof the blade'in all directions, blade-positioning means comprising fixed parts of: theholder-to. engage spaced parts of the blade and hold it in a'predetermined position-,-. and blade-backing means comprising a raisedportion of the/holder against which one surface ,of: the positioned-blade may rest, the

outermargins of the backingmeans being spaced inwardly from the-margins of theblade so as to hold themawayfrom-the adjacent parts ofthe holder, the portions of the tool facing and along the marginal portions of a positioned blade being inclinedat acute sharpening angles with respect to the surface of the blade, the mutually inter- .engaging portions of the tool and holder comprispart, the lugs being of an oblong form in crosssection, and each of the slots being of the form of a boot'having'its sole directed towards the near and of the flange, its leg towards the far end of the flange, its toe towards the base of the flange, its heel towards the free edge of the flange, and the entire boot tilted up slightly at the leg end about the toe, the major diameter of each lug being of greater length than the width of the part of the slot represented by the leg of the boot, and also of greater length than the distance from the part of the slot corresponding with the front of the leg near the toe to the back of the heel, the part corresponding with the toe of the boot being of a size such as to permit the lug to enter when'turned crosswise of the slot, and the form and size of the part corresponding with the heel being such as to permit the lug to turn freely when in theend of the slot to a position substantially crosswise thereof, in which position further movement will be prevented by the interlocking engagement between the part of the lug which enters the part of the slot represented by the toe of the boot and the adjacent walls of the slot.

. CHARLES E. BEARDSLEY. 

